Abrading tool



AUS- 30, 1932 L.. o. BEARD ABHADNG TOOL --Filed March 29, 1950 .NRU

NM1 Tw mw Patented Aug. 30, 1932 UNITED STATES ABRADIN'G rooL` Application led March29, 19310. Serial No. 440,131.3,

My invention relates to abrading tools and more particularly to that class of tools adapted yfor truing bushings in the piston pin bores of internal combustion engine pistons, although an abrading tool embodying the invention may be used for other work.

VThe principal object of the inventionis to so farm the usual spaced apart abrading members, and their seats in the tool shank, that a maximum ofbearing surface will be obtained, thus eliminating chattering.,

Another obj ect is to provide a tool in which parallel expansion of the abrading members may be readily effected. j

Another object of the invention is to `provide abrading members which may be readily mounted in the tool shank, and as easily re-V moved for repair or to permit the substitution of another abrading member.

I accomplish the above-mentioned and ,other related objects by the improved construction hereinafter described and claimed.

Of the accompanying drawing forming a part of this specification:

Figure 1.is a side elevation of a tool embodying the invention, and shows in outline a piston pin bearing to which the tool 1s applied;

Figure 2 is a side elevation of the tool shank with the abrading members removed;

Figure 3 is a longitudinal sectional view of the tool showing one of the abrading members mounted therein.

Figure 4 is a to 1 plan view of the abrading member shown in igure 3; and

Figure 5 is a section on the line 5 5 of Figure 4:.

Referring more particularly to the drawing wherein the same reference characters indicate like parts in all the figures, 1 reprents the shank of the abrading tool, which is formed with the smooth unthreaded intermediate portion 2 and adjacent threaded portions 3 and 4. The shank 1 is also provided vwith V-shaped longitudinal slots 5, of graduated depth, the bottoms 6 of the slots being inclined relative to the axis of the shank,

and the side walls 7 converging with each other.

Abrading members 9, V-shaped in cross LAWRENCE o. BEARD, or Lancasrnn,"

farej movably. inserted in the Vsaid slots,lfand yare 'provided withfbeveled end/,faces 10 and 11 engaged with the beveled ends of collars 12 and 413,in turn held inpla'ce .by f oniining .55 l

'liefe Mend; "115i awed upo ithe threaded portions 3 and L1:,'of the shank 1. The members 9 are shaped `to lit snugly within the i ends'lO engage the collar 12, and then screw- ..65 i

ing up the nut 15 to cause the collar 13 to engage the tapered ends 11, thus clamping the members 9 tightly in place. Parallel eX- pansion of the abrading members is accomplished byl loosening the nut 14 and screwing up the opposing nut, in a manner readily understood.

From the foregoing it will' be seen that by virtue of the V-shape construction of the slots and abrading members a two point bearing .L contact between the respective walls ofthe slots 5 and the sides n ofthe members 9 is secured, thus eliminating chattering.

The abrading members 9, are preferably made of the wellknown material from which emery wheels are made, for manufacturing use, where grinding or fast cutting is desired,

but where more laccurate work is required, these members are made of oil stone. some purposes such as -burnishing or rounding piston pin holes to provide a better bear.- ing surface, the members 9 may be made of For ".05

hardened and ground and polishedsteel, but

in all instances the shape and proportionswill be the same. v Y

` In actual manufacturing practice, vWhere lused on new work, thefends of the. tool shank are removably mountedV for rotation in any suitable machine. Onrepair work, the

tool is .inserted through the bores 16 of the piston 18, thus bringing the working vfaces 23 of the members 9 into engagement with the bushings 20, it being understood that the piston will preferably be clamped in a suitable vise, not shown, during the abrading operation. The reamer is then rotated by means of a crank or other suitable tool conneeted to the shouldered end portion 21.

However, it will ybe understood that the abrademployed on repair Work.v Y e Y Having thus described my invention, what Iclaim ist-l I f An abrading tool comprising a shank having tool may also be machine driven When ing elongated slots therein, said` slots being ofA *A graduated deptlr'and'having opposing out- Wardly diverging side Walls, and elongated. y4 y abrading members of graduated depth fitting Y snugly Within said slots,v the said `abrading j' membersv having substantially. unbroken abi'ading surfaces of relativelygreat Width andV inwardly diverging I' opposing sides Y adapted to seat vagainst the side Walls of the In testimony whereof IaiiX my signature.

i O. BEARDQ 

